From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: Linus' sha1 is much faster! Date: Sun, 16 Aug 2009 13:10:20 -0700 (PDT) Message-ID: References: <4A85F270.20703@draigBrady.com> <87eirbef3c.fsf@master.homenet> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Bug-coreutils@gnu.org, =?ISO-8859-15?Q?P=E1draig_Brady?= , Git Mailing List To: Giuseppe Scrivano X-From: bug-coreutils-bounces+gcgcb-bug-coreutils-616=gmane.org@gnu.org Sun Aug 16 22:10:56 2009 Return-path: Envelope-to: gcgcb-bug-coreutils-616@gmane.org Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1Mcm47-0004JY-5i for gcgcb-bug-coreutils-616@gmane.org; Sun, 16 Aug 2009 22:10:55 +0200 Received: from localhost ([127.0.0.1]:32812 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mcm46-0006dw-8U for gcgcb-bug-coreutils-616@gmane.org; Sun, 16 Aug 2009 16:10:54 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Mcm44-0006dr-DV for bug-coreutils@gnu.org; Sun, 16 Aug 2009 16:10:52 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Mcm3z-0006de-Pn for Bug-coreutils@gnu.org; Sun, 16 Aug 2009 16:10:52 -0400 Received: from [199.232.76.173] (port=45543 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mcm3z-0006db-Ip for Bug-coreutils@gnu.org; Sun, 16 Aug 2009 16:10:47 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:38193) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Mcm3x-0008Vq-1A; Sun, 16 Aug 2009 16:10:45 -0400 Received: from imap1.linux-foundation.org (imap1.linux-foundation.org [140.211.169.55]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id n7GKAKue028717 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 16 Aug 2009 13:10:21 -0700 Received: from localhost (localhost [127.0.0.1]) by imap1.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with ESMTP id n7GKAKdH003198; Sun, 16 Aug 2009 13:10:20 -0700 X-X-Sender: torvalds@localhost.localdomain In-Reply-To: <87eirbef3c.fsf@master.homenet> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.13 X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: bug-coreutils@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "GNU Core Utilities: bug reports and discussion" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: bug-coreutils-bounces+gcgcb-bug-coreutils-616=gmane.org@gnu.org Errors-To: bug-coreutils-bounces+gcgcb-bug-coreutils-616=gmane.org@gnu.org Archived-At: On Sun, 16 Aug 2009, Giuseppe Scrivano wrote: > > My GCC version is "gcc (Debian 4.3.3-14) 4.3.3" and the CPU is: Intel(R) > Pentium(R) D CPU 3.20GHz. Netburst is very sensitive to random spill effects, and you can basically tune things by just code shuffling that just has random effects on the generated asm code. > I also spent some time trying to improve the gnulib SHA1 implementation > and it seems a lookup table can improve things a bit. I pretty much can guarantee you that it improves things only because it makes gcc generate crap code, which then hides some of the P4 issues. I'd also suggest you try gcc-4.4, since that apparently fixes some of the oddest spill issues. Linus